Kikutani 1W mini amplifier RMS-10. Size: 125 x 125 x 155mm Rated output: 1W (RMS) Input: 1/4 phone jack x 1, External output: Headphone out x 1, with DC terminal Controls: Volume, Tone, Overdrive Speaker: 3 inches As shown in the photos, the battery cover on the back of the main unit is missing. I would like to sell this to someone who understands the above. In addition, I will include a nearly new 9V battery that was used for the operation check.